It has long been known to place fractures, particularly comminuted fractures, under distal fraction. Otherwise, compressive forces exerted on the healing bone will tend to collapse the bone. For healing comminuted finger bones (phalanxes), devices are in use which are attached to the arm and which hold the finger immobilized under distal traction.
One noted consequence of phalangeal fracture and the subsequent healing process is deterioration of cartilage tissue in the joints to which the fractured bone is connected, particularly the joint immediately proximal to the fractured bone. There is good medical evidence to suggest that the cartilage deterioration is, to a significant degree, a result of extended immobilization of the joints.
A number of studies relating to joint disorders suggest the value of subjecting injured or diseased joints to passive motion, which preferably is continuous. For example, Robert Salter, et al., Clinical Orthopedics and Related Research, No. 159, September, 1981, pp. 223-247, describe the beneficial effects of continuous passive motion on living articular cartilage in acute septic arthritis. Richard H. Gelberman, et al., The Journal of Bone and Joint surgery, 65A, pp. 70-80 (1983) describe the benefits of controlled motion in flexor tendon healing and restoration. As a result of such studies, various devices have been proposed to provide passive motion to damaged or diseased joints. These devices provide motion to phalangeal joints that are adjacent to fractures so as to afford the benefits which have previously been afforded to damaged or diseased joints, and at the same time, holding the fractured phalanx under distal traction. Movement has been found to assist in joint cartilage surface regeneration.
In order to accomplish such object, it is known to employ one such device that involves a splint having a substantially arcuate frame about which a motorized carriage travels for continuously flexing and extending phalangeal joints for joint healing and joint therapy. In such device, the fractured finger is attached to the motorized carriage under traction, and while being under traction, the carriage is reciprocated back and forth about the frame. An example of such device is disclosed in U.S. Pat. No. 4,607,625 issued to Robert R. Schenck.
Such device is highly effective in the healing and maintaining the anatomical structure of fractured phalanxes. However, it is further desirable to provide this type of healing and joint therapy with a device that tends to be more suitable for custom adaption to a particular patient. The aforementioned patent discloses a motor mounted for travel along an arcuate track in a circular hoop or ring. Motors are relatively heavy and their position substantially outward of the person's fingertips makes the device feel very heavy and very awkward to the wearer. Cost of the device is particularly relevant. Some companies will only lease the devices for use at relatively high cost per usage.
It is the primary object of the present invention to provide a device which is inexpensive and can be sized on a particular patent basis to increase the comfortability and portability of the device. In this connection, the present invention is directed to a device which accomplishes the desired healing and therapeutic results while enhancing transportability. In particular, the present invention focuses on the reduction of the device's weight and awkwardness through the reduction of the frame size and the design and positioning of the device's means for reciprocating the carriage for flexing the joints.
Another objective is to provide a dynamic traction device which alternately flexes and bends a fractured joint, and yet which is highly durable, efficient and cost effective to manufacture, install and operate.